Natural gas leaks create both safety and environmental hazards, and occur along the entire gas supply chain from the well to the street (so-called upstream, midstream, and downstream sectors). Methane, the primary constituent of natural gas is combustible in air, and is also a potent greenhouse gas. Other hydrocarbons found in natural gas, as well vapors emanating from liquids separated from gas and oil include ethane, propane, butane, pentane, hexane, octane, and heavier hydrocarbons, which form volatile organic compounds that generate smog which is a health hazard. Thus, there are compelling reasons to detect leaks of gases comprising, for example, methane and other hydrocarbons, so that such leaks can be repaired.
Beyond merely detecting presence of leaking gas, localizing leaks and quantifying their leak rate (e.g., emission flux of leaking gas) are important for allowing repair of leaks to be performed rapidly, and in a prioritized fashion. Quantification of leak rate also allows the impact (e.g., environmental impact) of leaking gas to be assessed. Detection, localization, and quantification of gas leaks is challenging, since leak monitoring and/or inspection typically need to be performed over wide areas, and from a safe and practical standoff distance. The presence of naturally occurring ambient gases and vapors, such as water vapor, also poses challenges, since leaking gas of specific compounds of interest needs to be distinguished from such ambient gases.
Accordingly, there exists a need for improved systems and methods for detection, localization, and quantification of gas leaks. In particular, there is a need for systems and methods that allow for effective gas leak monitoring and/or inspection to be performed over wide areas, and even in the presence of interfering background signals. Cost effective solutions are particularly important, as they can be broadly adopted and utilized.